1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle 7 * Copyright (C) 1996 by Paul M. Antoine 8 * Copyright (C) 1999 Silicon Graphics 9 * Copyright (C) 2000 MIPS Technologies, Inc. 10 */ 11 #include <asm/irqflags.h> 12 #include <asm/hazards.h> 13 #include <linux/compiler.h> 14 #include <linux/preempt.h> 15 #include <linux/export.h> 16 #include <linux/stringify.h> 17 18 #if !defined(CONFIG_CPU_HAS_DIEI) 19 20 /* 21 * For cli() we have to insert nops to make sure that the new value 22 * has actually arrived in the status register before the end of this 23 * macro. 24 * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs 25 * no nops at all. 26 */ 27 /* 28 * For TX49, operating only IE bit is not enough. 29 * 30 * If mfc0 $12 follows store and the mfc0 is last instruction of a 31 * page and fetching the next instruction causes TLB miss, the result 32 * of the mfc0 might wrongly contain EXL bit. 33 * 34 * ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008 35 * 36 * Workaround: mask EXL bit of the result or place a nop before mfc0. 37 */ 38 notrace void arch_local_irq_disable(void) 39 { 40 preempt_disable_notrace(); 41 42 __asm__ __volatile__( 43 " .set push \n" 44 " .set noat \n" 45 " mfc0 $1,$12 \n" 46 " ori $1,0x1f \n" 47 " xori $1,0x1f \n" 48 " .set noreorder \n" 49 " mtc0 $1,$12 \n" 50 " " __stringify(__irq_disable_hazard) " \n" 51 " .set pop \n" 52 : /* no outputs */ 53 : /* no inputs */ 54 : "memory"); 55 56 preempt_enable_notrace(); 57 } 58 EXPORT_SYMBOL(arch_local_irq_disable); 59 60 notrace unsigned long arch_local_irq_save(void) 61 { 62 unsigned long flags; 63 64 preempt_disable_notrace(); 65 66 __asm__ __volatile__( 67 " .set push \n" 68 " .set reorder \n" 69 " .set noat \n" 70 " mfc0 %[flags], $12 \n" 71 " ori $1, %[flags], 0x1f \n" 72 " xori $1, 0x1f \n" 73 " .set noreorder \n" 74 " mtc0 $1, $12 \n" 75 " " __stringify(__irq_disable_hazard) " \n" 76 " .set pop \n" 77 : [flags] "=r" (flags) 78 : /* no inputs */ 79 : "memory"); 80 81 preempt_enable_notrace(); 82 83 return flags; 84 } 85 EXPORT_SYMBOL(arch_local_irq_save); 86 87 notrace void arch_local_irq_restore(unsigned long flags) 88 { 89 unsigned long __tmp1; 90 91 preempt_disable_notrace(); 92 93 __asm__ __volatile__( 94 " .set push \n" 95 " .set noreorder \n" 96 " .set noat \n" 97 " mfc0 $1, $12 \n" 98 " andi %[flags], 1 \n" 99 " ori $1, 0x1f \n" 100 " xori $1, 0x1f \n" 101 " or %[flags], $1 \n" 102 " mtc0 %[flags], $12 \n" 103 " " __stringify(__irq_disable_hazard) " \n" 104 " .set pop \n" 105 : [flags] "=r" (__tmp1) 106 : "0" (flags) 107 : "memory"); 108 109 preempt_enable_notrace(); 110 } 111 EXPORT_SYMBOL(arch_local_irq_restore); 112 113 #endif /* !CONFIG_CPU_HAS_DIEI */ 114